The unexpected appearance of Dawes' observatory on the '1808 Sydney Cove Map'

In commemoration of Australia's 1988 Bicentenary celebrations, a public artwork in the form of a large 'terrazzo' and brass map was realised on the site of Sydney's earliest British settlement. The 3.6 metre-diameter map was intended to show the topography of Sydney Cove as of 1808. Surprisingly, the map includes a cluster of buildings that are clearly identifiable as Dawes' Observatory, established by Lieutenant William Dawes in 1788. However, Dawes' Observatory became derelict shortly after the astronomer's departure from New South Wales in late 1791, with little evidence of its existence remaining by the mid-1790s. I contend that the '1808 Sydney Cove Map' is likely a representation of the topography of the growing settlement at Sydney Cove during an extended period up to 1808. Although the majority of topographical features were taken from the 1807 survey by the fledgling colony's Surveyor-General, James Meehan, the reliance by the Sydney Cove Map's designers on a range of historical sources that covered a time span of 20 years has inadvertently introduced an anachronism by also including Dawes' Observatory.